Azomethine dyes from acylacetamidobenzaldehyde acetals



pounds which have the properties of dyes.

Patented June 14, 1949 i AZOMETHINE'DYES FROM ACYLACETA- MIDOBENZALDEHYDE ACETALS David Malcolm McQueen, Wilmington, DcL, as-

signor to E. L dn Eont de Ncmours & Company, Wilmington, Del., a corporation of Delaware NoDrawing. Application April 17, 1948;

- Serial No. 21,761

6 Claims. (01. zoo-33s) This invention relates to new organic chemical compounds and more particularly to such com- Still more particularly it relates to novel azomethine dyes.

'Anobject of this invention is to provide a new class of organic compounds which have the prop,- erties of dyes. A more specific object is to pro vide new azomethine dyes from a class of novel acylacetamidobenzaldehyde acetals. An: other object is to provide a new class of dyes which have general utility in the textile arts. Still other objects will be apparent from the following description of the invention.

The novel chemical compounds of this invention are m (acyl-[4'-(dialkylamino)phenyliminoacetamido) -benzaldehyde acetals of alkanols of 1 to 4 carbon and 1,2- and 1,3-alkanediols of 2 to 4 carbon atoms. They may be represented by the general formula:

acyl radical, R." is an alkyl radical of 1 to 4 carbon atoms and Y and Y alone are alkyl radicals.

of 1 to 4 carbon atoms and whenjoined constitute a' saturated aliphatic divalent hydrocarbon radical of 2 to 4 carbon atoms where 2 tov 3 atoms are in the chain between the two oxygen atoms. In the above formula, B may be a 'fatty acid acyl radical'of 1 to 11 carbon atoms, e. g.,

ll n-ccan be acetyl, propionyl, and decanoyl; or other acyl radicals such as toluoyl, ethylbenzoyl, benzoyl, a-naphthoyl, fl-naphthoyl, furoyl, carbalkoxy radical etc., but R is preferably a hydrocarbon radical; Y and Y may be methyl, ethyl; n-propyl. v

isopropyl, n-butyl and isobutyl or together may 2 constitute the radical of a 1,2- or 1,3-glycol of 1 to 4 carbon atoms, e. g.,, dimethylene or trimethylene. Y and Y together are preferably -CH2CH2-- and o nitis preferably acetyl or benzoyl.

The-novel compounds of the above formula can be prepared by reacting an acetal oi the formula:

OY 2) n n' cinc ON- wherein R and Y and Y have the same significance as in Formula 1 with a p-aminodialkylaniline, e. g., p-aminodiethylaniline, inthe presence of a mild oxidizing agent under alkaline conditions, e. g.,exposed light-sensitive silver halide, or potassium ferricyanide. The dye which separates or precipitates out. can be filtered,.washed and dried, and purified by extraction and recrystallization.

The acetals of Formula ,2 can be advantageously prepared by reacting an acylacetic acid ester, e. g., ethyl acetoacetate or ethyl benzoylmonoalkanol, e. g., ethyl acetoacetate, and an in-.

ert high-boiling solvent, e. g., chlorobenzene or xylene, and a small amount of an alkaline catalyst, e. g., pyridine, 20% aqueous NAOH, etc., are heated to a temperature of to C. The acetal of meta-aminobenzaldehyde, for example, maminobenzaldehyde ethylene glycol acetal, is then added. Theethyl alcohol formed in the condensationreaction is distilled out of the mixture over aperiod of two to four hours. After cooling, the reaction mixture is poured into water containing a sufficient amountof sodium hydroxide "to dissolve the m-acetoacetamidobenzaldehyde acetal. The water layer is separated, washed with a water-immiscible solvent, such as ether, and is saturated with carbon dioxide. The m-acetoacetamidobenzaldehyde acetal separates as a solid or, in some cases, an oil. The material may be further purified by repeated extractions or crystallization from suit- The dyes this invention are useful as colorable lvent ing materials for textiles. They may be applied The m-aminobenzaldehyde acetals used as tocotton,viscoserayon.wool,silkornylon fabrics startin materials may be prepared in any sultby first reducing to the soluble form by methods able fashion; for example. by the method de- 5 gener lly employed for vat colors followed by scribed in J. Chem. Soc, 121, '76 (1922). Howreoxidation in the impregnated fabric with air ever, the preferred method of preparing mor mild oxidizing agents. For example, these aminobenzaldehyde acetals involves the acetalicolors are produced by first reducing the dye in zation of m-"itrobenzaldehyde followed by cataaqueous suspension to the leuco form with sodium lytic reductic with hydrogen. 1o hydrosulflte and alkali using procedures normally This invent ion is further illustrated by the employed for vat dyes. Then the textile fabric is following example in which parts are by weight. immersed in the dyebatb. at 80-90 C. for periods Example p o One hour or longer. It is then removed,

A solution of 6.22 parts of m-(benzoylacetbichromate solution. In this manner brilliant amidolbenzald hyd yl n ly M l hflvyellow colors are obtained on the fabric having ing a melting point of 101 to 102 C. in 200 parts excellent fastness to washing. of water containing 6.5 parts of dium hydroxide Although the vat process involving reduction is added to a solution of 4 parts of p-aminois the preferred method of applying these dyes diethylaniline hydrochloride in 150 parts of to textile fibers to achieve good penetration of water. To this is added successively 18 parts oi color, they can also be applied directly. 1. e., ammonium bromide in 50 parts 01' water and 28 without prior reduction. This method is particuparts of silver nitrate in 30 parts of water and larly applicable to the utilization of these dyes as the solution stirred for 30 minutes while being throwster colors. exposed to light. The yellow a om ne dye As many widely diiierent embodiments of this which forms is collected on a filter and washed invention can be made without departing from well with water and dried. This crude dye mixthe spirit and scope thereof, it is to he understood ture is extracted with methylene chloride and thatthe invention is not to be limited except as the extract concentrated to about 75 parts and defined by the claims.

150 parts of petroleum ether are added to it. What is claimed is:

An oily. yellow dye separates and is dried to ohi. The compounds taken from the group contaln a dark brown powder, soluble in benzene. sisting of those oi the formula:

ether and alcohol. The yield is 4.5 parts of dye melting at 54-56" C. This dye is purified by H 0-alky chromatographic adsorption by passing 9. ben- '00o-N cn zene solution through a column of alumina. By Y washing with benzene containing 2 to 10% of methyl acetate, several bands separate. the first of which is a light yellow impurity, the second I being the desired yellow dye, and the third a 40 purple impurity. The middle fraction is isolated and the solvent removed to obtain the pure dye melting at 47-48" C. and having the formula 0-011, and

H g Y 0CHR Q E CON l w-c-coch (6112) CsHl n N c... i Other dyes can be prepared by substituting for the m-(benzoylacetamido)benzaldehyde ethylene Where R i cerbm'lic i acyl radical of 2 glycol acetal other m-(acylacetamido)benzalde- 11 mm atoms. n a kyl radical of 1 to hyde ethylene glycol acetals including m-(aceto- 4 carbon atoms G contains 1 to 4 carbon acetamido) benzaldehyde ethylene glycol acetal, awms- R is men from the group s ng of m-(furoylacetamido) benzaldehyde ethylene glyhydmgen and methyl and n is a n m er taken col acetal, m-(a-pioolinylacetamido)benzaldef the group consisting of 0 and 1. hyde ethylene glycol acetal, m-(o-anisoylacet- The compounds the ral formula: amido) benzaldehyde ethylene glycol acetal, which 043m can be prepared after the manner described above H g and in application Serial No. 667,126. The correo-N sponding dimethyl, diethyl, di-n-propyl, diiso- A 1% o H, propyl, diisobutyl, di-n-butyl, Lil-propylene glycol, and 1,3-butylene glycol acetals of the above can be used in like manner.

In place of the p-aminodiethylaniline hydro- 7 chloride described above, there may be substi- N tuted p-aminodimethylaniline hydrochloride,

p-aminodipropylaniline hydrochloride, or paminodibutylaniiine hydrochloride. The sulfates where alkyl contains 1 to 10 carbon atoms and and other salts can be used, if desired. R" is an alkyl radical oi 1 to 4 carbon atoms.

8. The compounds 0! the tormula: 5. The compounds of the formula:

ocm 3 9 cm-0- C 0004-00. c\ l I a 1% o- H, 5

n" a" 10 r/ n" whemR is an alkyl Ia no 81 o! 1 to who where R is an alkyl radical of 1 to 4 carbon atoms atoms.

4. The compound of the Iormula: 15 6' The compound of the formula: 0 on a v H 0-4311: I O0 0-0-0 0-?1- C m-c-c-oon 0 1m ([5 1k \0- H, I 0- HI 7 2o omom. N/ N/ mum 0am I I DAVID MAIBOLM No references cited Certificate of Correction Patent No. 2,472,913. June 14, 1949.

DAVID MALCOLM MCQUEEN It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correctlon as follows:

Column 4, lines 63 to 68, inclusive, claim 2, for that portion of the formula reading 0-011; O-OH| gm gm.

column 6, lines 16 to 20 inclusive, claim 6, for

H H N N 0 read 0 and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case 1n the Patent Office.

Signed and sealed this 15th day of November, A. D. 1949.

THOMAS F. MURPHY,

Assistant Oommiuioner of Paton. 

